The authors state that while Pons and Fleischmann were criticized for their claims, isotopic shifts in room-temperature experiments had been observed by some researchers, specifically tritium production and low-level neutron emissions.

Krivit and Ravnitzky favor the theories of Lewis Larson and Allen Widom to explain these phenomena, which are based on weak interaction, and which do not require any fusion to take place. The Widom-Larson theory has been seen by others as an explanation for LENR results which does not violate known physics, and which explains some of the unusual occurrences in LENR experiments. The authors write:

For nearly three decades, researchers in the field have not observed the emission of dangerous radiation. Heavy shielding has not been necessary. The Widom-Larsen theory offers a plausible explanation—localized conversion of gamma radiation to infrared radiation. The implication is that immense technological opportunities may exist if a practical source of energy can be developed from these laboratory curiosities.

Widom-Larsen theory is certainly not the only attempt to explain what is going on in LENR, but it seems to have a certain amount of respectability, in that it rules out room-temperature fusion, the idea which was so anathema to many in mainstream science when the cold fusion story broke. Scientific American seems to feel comfortable now at least allowing a discussion of LENR on its site, without automatically labeling it as junk science. I think this shows some progress.